SOLUTION: A veterinarian surveys 40 of his patrons. He discovers that 15 have dogs, 16 have cats, and 11 have fish. Six have dogs and cats, 8 have dogs and fish, and five have a cat and a fi

Algebra ->  Probability-and-statistics -> SOLUTION: A veterinarian surveys 40 of his patrons. He discovers that 15 have dogs, 16 have cats, and 11 have fish. Six have dogs and cats, 8 have dogs and fish, and five have a cat and a fi      Log On


   

Question 1028072: A veterinarian surveys 40 of his patrons. He discovers that 15 have dogs, 16 have cats, and 11 have fish. Six have dogs and cats, 8 have dogs and fish, and five have a cat and a fish. If two or them have all three kinds of pets, how many patrons have none of these pets?
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
You can solve this by using three intersecting circles...kinda hard to show here...but the advice is to start from the inside and work your way out...start from 2 in the central region where all three circles intersect and go from there...it isn't clear whether those that have dogs and cats can also have fish, but assuming that is so, I get 15 people have none of those...